| 摘要 |
PURPOSE:To prevent reaction of a recording layer with a protective layer and to enable stable recording and erasing for several million cycles by varying the composition of the protective layer in the thickness direction in a manner that the proportion of a specific compound is larger in the interface area adjacent to the recording layer. CONSTITUTION:On the first dielectric layer 2, a protective layer 3, recording layer 4 and again the protective layer 3 are successively formed, the second dielectric layer 5 is provided thereon and further a reflecting layer 6 is provided. The composition of the protective layer 3 essentially comprising such a compound which does not make a solid solution with chalcogenides is varied in the thickness direction in a manner that the proportion of the compound is larger in the interface area adjacent to the recording layer 4. By this method, the reaction between the recording layer and the protective layer is inhibited to prevent deterioration of the recording layer. Thus, the medium has stable characteristics of recording and erasing for several million cycles. |
